Lockstitch shoe sole sewing machines



Sept. 18, 1962 J. R. lOANNlLLl LOCKSTITCH SHOE SOLE SEWING MACHINES l8 Sheets-Sheet 1 Filed July 25, 1958 In venfor se vh R. foann LZZZ; By hzQS/l fern/6y Sept. 18, 1962 J. R. [OANNILLI 3,054,365

LOCKSTITCH SHOE SOLE SEWING MACHINES Filed July 23, 1958 18 Sheets-Sheet 2 Sept. 18, 1962 J. R. IOANNILL] LOCKSTITCH SHOE SOLE SEWING MACHINES 18 Sheets-Sheet 3 Filed July 25, 1958 Sept. 18, 1962 J. R. iOANNlLLl 3,054,365

' LOCKSTITCI-I SHOE SOLE SEWING MACHINES Filed July 25, 1958 18 Sheets-Sheet 4 p 1962 J. R. IOANIIWLLI 3,054,365

LOCKSTITCH SHOE SOLE SEWING MACHINES Filed July 23, 1958 18 Sheets-Sheet 5 Sept. 18, 1962 J. R. IOANNILLI LOCKSTITCH SHOE SOLE SEWING MACHINES l8 Sheets-Sheet 6 Filed July 23, 1958 Sept. 18, 1962 J. R. IOANNILLI LOCKSTITCH SHOE SOLE SEWING MACHINES l8 Sheets-Sheet 8 Filed July 25, 1958 Sept. 18, 1962' J. RLIOANNILLI 3,054,365

LOCKSTITCH SHOE SOLE SEWING MACHINES Filed July 25, 1958 18 Sheets-Sheet 9 Sept. 18, 1962 J. R. lOANNlLLl 3,054,365

LOCKSTITCH SHOE SOLE SEWING MACHINES Filed July 23, 1958 18 Sheets-Sheet l0 P 1952 J. R. lOANNlLLl 3,054,365

LOCKSTITCH SHOE SOLE SEWING MACHINES Filed July 25, 1958 18 SheetsSheet 11 f; 22 52 .i J12 112 Sept. 18, 1962 J. R. lOANNlLLl 3,054,365

LOCKSTITCH SHOE sous SEWING MACHINES Filed July 23, 1958 18 Sheets-Sheet l2 J. R. IOANNILLI LOCKSTITCH SHOE SOLE SEWING MACHINES Sept. 18, 1962 18 Sheets-Sheet 13 Filed July 25, 1958 Sept. 18, 1962 J. R. IOANNILLI LOCKSTITCH SHOE SOLE SEWING MACHINES l8 Sheets-Sheet 14 Filed July 25, 1958 Sept. 18, 1962 J. R. IOANNILLI LOCKSTITCH SHOE SOLE SEWING MACHINES Filed July 25, 1958 Sept. 18, 1962 J. R. IOANNILLI LOCKSTITCH SHOE SOLE SEWING MACHINES 18 Sheets-Sheet 16 Filed July 23, 1958 p 1962 J. R. lOANNlLLl 3,054,365

LOCKSTITCH SHOE SOLE SEWING MACHINES Filed July 23, 1958 18 Sheets-Sheet 17 J. R. IOANNILL! 3,054,365

Sept. 18, 1962 LOCKSTITCH SHOE sou; SEWING MACHINES l8 sheets-sheet 18 Filed July 23, 1958 United States Patent 3,054,365 LOCKSTITCH SHOE SOLE SEWING MACS Joseph R. loanmili, Beverly, Mass, assignor to United Shoe Machinery Corporation, Boston, Mass, a corporation of New Jersey Filed July 23, 1958, Ser. No. 750,392 35 Claims. (Cl. 112-32) The present invention relates to lock stitch shoe sole sewing machines and, more particularly, to improvements in the type of sewing machine which is provided with locking loop forming and inserting devices as distinguished from the type having a locking thread carrying shuttle, about which each loop of machine or needle thread is passed in forming a conventional lock stitch seam. In certain of its features, however, the invention is not limited to shoe sewing machines of the loop lock form but is capable of use to advantage with machines for insert ing stitches of other forms. In other respects the invention is intended to facilitate and simplify the operation of machines similar to that disclosed in an application for United States Letters Patent Serial No. 543,321, filed October 28, 1955 in my name (now Patent No. 2,877,725, granted March 17, 1959).

In sewing a shoe outsole by machine a problem always has existed at the end of a sewing operation to provide a simple trouble-free method of severing the thread running from the machine to the shoe. The usual practice is to provide means for releasing the tension on the thread in the machine so that the shoe together with a substantial length of thread may be Withdrawn until the shoe may be turned to a position where the thread may be trimmed so close to the surface of the shoe sole that its end is inconspicuous. In spite of many attempts to provide automatic devices for severing thread with this type of machine, none has proved satisfactory heretofore for a number of reasons, among which are:

(1) The difficulties of maintaining a keen cutting edge on a thread severing knife;

(2) Preventing displacement of the final stitch in a seam by reason of tension exerted on the thread while being severed by a dull knife;

(3) Providing the proper length of thread for starting a new seam;

(4) Complete severance of the thread to avoid unsightly fringed ends;

(5) Withdrawing a length of thread from the machine before severing so that another trimming operation is required to remove an excessive length extending from the first stitch in a new seam; and

(6) Waste of thread in trimming.

A preferred practice, therefore, still comprises severing thread from a shoe at the end of a seam by employing a hand-held knife and withdrawing only that amount of thread with the shoe at the end of a seam needed for severing closely to the shoe where the thread end will be inconspicuous.

The thread required in sewing shoes either with welts, insoles and uppers for an inseam or with welts and outsoles for an outseam is of such large size that the resistance offered to the passage of a knife edge contributes to the problem of severing the thread, which is generally impregnated with wax or other compound to lubricate its passage through the shoe parts, to seal the interstices between thread fibers against entry of contaminating materials and to seal the perforations formed by the stitches after insertion. For these reasons the difficulties are far greater than are met with light weight sewing machines employing a dry thread of a size which may readily be broken merely by tension exerted on the final stitch of a seam.

When utilizing a hand-held knife it is usual in cutting a thread to direct the edge of the knife against a surface of the shoe as a cutting block, so that complete severance is insured and displacement of the last formed stitch in a seam as the result of tension exerted by the knife is avoided. Cutting the thread against the shoe always causes damage to the shoe, so that care must be taken in selecting a surface which will thereafter be covered up by other parts, such as that portion of a bottom surface obscured by a later applied heel.

It is an important object of the present invention to simplify the operation of a shoe sole stitching machine by the provision of automatic means for severing the sewing thread with greater reliability than heretofore, so close to the surface operated upon that in starting a new seam the end of the thread remaining in the machine will be drawn close to or fully into the work to a position where it is inconspicuous, not requiring trimming or further attention on the part of the machine operator. In this connection it is also an object to provide thread severing devices of such nature that there is no danger of exerting an excessive stitch displacing tension on the thread running to the scam, the last formed stitch always being left in the same position at which it was finally set in the substance of the shoe. Further objects of the invention are to provide a work support having an electrically heated thread severing member mounted thereon and an improved form of said thread severing member particularly adapted for use in a wax thread curved needle sewing machine, wherein space limitations are highly restricted and the problem of heat insulation is particularly troublesome.

Other objects of the invention, more particularly relating to a sewing machine having loop lock forming and inserting devices, include improving the arrangement and mode of operation for a needle loop retractor and a locking threaded loop carrying and inserting finger mechanism, so arranged that a more reliable construction than heretofore is obtained with greater durability and ease of operation than in the machine of the prior application. It is also :a purpose of the invention to improve the operation of the prior machine by the addition of thread pulloff devices acting in stopping and starting the machine to insure accurate and reliable positioning of the end of the thread remaining in the machine for successfully forming a new stitch in a seam.

It has been found that threads ordinarily employed in sewing machines and particularly those of the shoe sole sewing type are subject to relatively heavy stresses approaching and frequently surpassing their yield points during normal sewing operations. In a shoe sole sewing machine these yield points may reach an intensity of pounds under operating conditions of normal temperature and humidity. To reduce the possibility of yielding beyond their elastic limits and otherwise to improve the seams inserted, it is common to treat sewing threads before use with solutions of waxes, resins, and other fiber modifying materials. Frequently, the characteristics of thread are further improved by a moderate application of heat controlled carefully to avoid any approach to that temperature which will reduce the yield point appreciably. One purpose for the thread treatment is to retain uniformly in the thread a maximum amount of tensile strength consistent with toughness and elastic capabilities. The use of fiber modifying materials and moderate heat, however, increases the difficulties met in the use of a knife edge for severing the thread in a sewing machine.

Instead of depending upon the use of a knife edge to sever the thread in a sewing machine, of the type referred to, the present invention proposes the use of thread severing means arranged to be engaged with the thread at the end of a seam and heated to a relatively hightemperature above that which begins to reduce the tensile strength of the thread to such an extent that it is rendered capable of-unlimited yielding action under a relatively light pull exerted against the last formed stitch in the seam without displacing that stitch. For so doing the heat of the severing means acts to evaporate the fiber modifying solutions on the thread and is constructed to be mounted directly on one member of a clamp for the Work piece, so close to the work-engaging surface thereof that the thread may be severed with an inconspicuous end remaining on the work piece without heating the Work piece to a temperature which will be injurious to the latter. Preferably, a nipper jaw also is mounted on the work clamp in a manner to deflect the thread into engagement with the heated severing member, so as to exert a severing pull on the thread, as well as to hold the severed end remaining in the machine at a position conducive to the proper formation of the first stitch in a new seam. In its illustrated form the severing means comprises an electrical resistance member, the tempera- 4 accomplished by connecting it to the driving and stopping mechanism. A

Other features of the invention consist in the devices, combinations and arrangements of parts as hereinafter described and claimed, the advantages of which will readily be understood from the accompanying drawings, in which:

FIG. 1 is a view in front elevationof the left hand portion of a shoe outsole stitching machine, including features of the present invention, parts of the machine having been broken away and reduced in height to enable the use of a larger scale in the remaining parts of the illustration.

ture of which is controlled by a heating circuit containing an energizing switch and other essential components.

The needle thread loop retractor, according to a feature of the invention, co-operates with a loop spreader and the needle, each loop of needle thread being withdrawn from the work in the form of an open triangular loop which defines a plane at an angle to the line of the seam being inserted, together with actuating mechanism effective to cause the spreader to enter each loop of thread from that side of the point of operation opposite to the completed stitches of a scam, the retractor both engaging and lifting the thread from the needle hook with a continuous movement.

Instead of employing a locking thread carrying finger, such as disclosed in my prior application, which finger enters each spread loop of needle thread from outside the arc of, curvature of the curved. needle, it has been found that a marked improvement in operation of the present machine and an improved facility for present ing a shoe is obtained by arranging the mechanism for actuating the present improved locking thread carrying finger in such a way that it enters each needle loop from within the arc of needle curvature. By actuating the locking thread carrying finger from within the arc of needle curvature, greater visibility is afforded about the sewing point for the operator and less opportunity for interference is given between the locking thread finger and the shoe being presented to the machine.

The loop lock stitch sewing machine of the prior application employs means for measuring a predetermined length of thread for each stitch and at least one thread lock co-op'erating with the measuring means is provided against which thread lock each stitch is set in the work. In order to facilitate the insertion of the first stitch in a new seam, particularly in machines employing a thread rest;

FIG. 2 is an enlarged view of a portion of the machine shown in FIG. 1; FIG. 3 is a sectional view on an enlarged scale, looking along the line III-III of FIG. 2 and showing the position of a shoe at the end of a seam in the machine of that figure;

FIG. 4 is a view in rear elevation and on a slightly reduced scale of a portion of the driving and stopping mechanism in the machine;

FIG. 5 is a similar view on a larger scale of a portion of the mechanism shown in FIG. 4*but with additional parts broken away to illustrate more clearly the underlying parts of 'FIG. 4;

FIG. 6 is a detail view in right side elevation of a treadle connected part in the driving and stopping mechanism of FIG.'5;

FIG. 7 is a plan view of a portion of the same mechanism showing a locking thread pull-off with the parts illustrated in positions assumed while the machine is at FIG. 8 is a similar view of the parts of the locking thread pull-off in positions assumed while sewing operations are continuing;

FIG. 9 .is a sectional detail view in rear elevation on a somewhat enlarged scale taken along the line IX--IX of FIG. 8;

FIG. 10 is a sectional detail view on a somewhat smaller scale, looking from the right side of the machine and illustrating the positions of the parts just before the machine comes to rest .at the end of a seam;

cutter,,an essential degree of accuracy required in start ing a new seam without trimming thread extending from the first stitch is obtained in the illustrated machine by providing a pull-off located along the length of thread running from the thread lock to thethread supply. The pull-off with this feature of the invention is actuated at the end of a seam while the thread lock remains closed, so that there is no possibility for the take-up to withdraw; the thread end from its proper position in forming and setting the'first stitch of a new seam. Thus, the 'thread'lock serves two purposes; one to assist the measuring means in withdrawing thread in the proper predetermined length from the supply for completion of each stitch in a seam and the other to prevent displacement of the thread end during operation of the pull-ofi at the end of the seam. Where, as in the present instance, a driving and stopping mechanism controls the operation ofthe machine, the proper operation of the pull-off is FIG. ll is a similar view of some of the parts in front of those shown in FIG. .10, illustrating their positions during sewing operations;

FIG. 12 is an enlarged front view of portions of the machine surrounding the point of sewing operations, illustrating a locking thread severing member;

FIG. 13 is a detail view. in right side elevation showing the operations of the locking threadsevering member on a shoe illustrated in section;

FIG. 14 is a view in left side elevation of the locking thread severing member in a modified for-m having a thread directing guard to insure proper engagement of the thread therewith;

FIG. 15 is a detail view in front elevation of the locking thread severing member;

FIG. 16 is a sectional detail view in left side elevation illustrating a thread measuring action performed by the locking thread measuring member;

v FIG. 17 is a sectional detail view on a further enlarged scale of a locking thread friction device as viewed in the direction of the arrow XVII in FIG. 16;

FIG. 18 is a detail plan view of a needle thread severing member mounted on the work support ofthe machine, together with a thread end clamping device;

FIG. 19 is a sectional detail view in front elevation of the parts in the machine surrounding the sewing point and including the thread end clamping device;

FIG. 20 is asectional detail'view in frontelevation and on a slightly enlarged scale, looking along the line XX-XX' of FIG. 18, and showing the construction of 

